Marcus Gunn Syndrome - A Rare Neural Misdirection Phenomenon Case Report.

Rationale: This case report describes the Marcus Gunn phenomenon (MGP), an infrequent type of congenital unwanted contractions of facial muscles that occurs in 4%-6% of patients with congenital ptosis. The defining characteristic of MGP is the affected eyelid lifting in a manner similar to the opening of the mouth. Patient Concerns: It addresses a 45-year-old man who was examined in the dental clinic with a severely decayed tooth. He exhibited evidence of normal vision and synchronous movement of his lips and eyelid. Diagnosis: The conditions matched those of the autosomal dominant disorder with incomplete penetration, the MGP. The carious tooth was restored without the necessity for any surgical intervention. Treatment: The patient was given appropriate dental treatment without any surgical intervention for Marcus Gunn Syndrome. Outcome: After receiving routine fillings to treat dental caries, the patient stopped complaining of pain. Take-away Lesson: This case report reveals insight into a situation that has been speculated to be an example of neural redirection syndrome, in which impulses from the trigeminal nerve's motor unit are naturally redirected into the levator palpebrae superioris muscles of the upper eyelid and the superior pterygoid muscle.

Síndrome de Marcus-Gunn / Marcus Gunn syndrome

Introducción: El síndrome de Marcus-Gunn se manifiesta con retracción o elevación del párpado ptótico ante la estimulación del músculo pterigoideo del mismo lado y el término "guiño mandibular" es inapropiado ya que el párpado no siempre desciende. Puede producirse en la apertura bucal, masticación, avance mandibular, al sonreír, silbar, bruxar, sacar la lengua, deglutir, chupar, cantar, en la contracción esternocleidomastoidea, maniobra de Valsalva, respirar o inhalar. Es congénito y de modalidad rara y autosómica dominante. Objetivo: Contribuir al conocimiento de esta rara enfermedad y a su relación con el ámbito odontológico. Presentación del caso: Se trata de un niño de 3 años diagnosticado de síndrome de Marcus-Gunn en el periodo neonatal, por la observación de la madre de una apertura palpebral izquierda durante la succión nutritiva. No presenta otras enfermedades ni antecedentes de interés. En la exploración extraoral se advierte una ptosis palpebral derecha y apertura palpebral izquierda en los movimientos mandibulares y deglución. La intensidad del reflejo se incrementa en estados de ansiedad derivados del tratamiento dental. Conclusiones: el síndrome de Marcus-Gunn es una entidad rara en pediatría, en la cual sus hallazgos clínicos determinan el diagnóstico. Teniendo en cuenta que en ocasiones presentan alteraciones oculares, nada nos hace sospechar la presencia de una enfermedad oral específica(AU)

Introduction: Marcus Gunn syndrome manifests with retraction or elevation of the eyelid ptotico while stimulation of the pterygoid muscle on the same side and the term jaw-winking is inappropriate because the eyelid does not always goes down. It can occur during mouth opening, mastication, mandibular advancement, while smiling, whistling, bruxing, sticking out the tongue, swallowing, sucking, singing, during the sternocleidomastoid contraction, the Valsalva maneuver, breathing or inhaling. This syndrome is congenital and rare, and of autosomal dominant modality. Objective: To contribute to the knowledge of this rare disease and its relationship with the odontologic field. Presentation of the case: 3 years old boy diagnosed with Marcus Gunn syndrome in the neonatal period by the observation of the mother of a left palpebral opening during the nutritive sucking. He does not present other diseases or a background of interest. In the extraoral exploration, it is noticed a right palpebral ptosis and a left palpebral opening in the jaw movements and in swallowing. The intensity of the reflex increases in anxiety states arising from the dental treatment. Conclusions: Marcus Gunn syndrome is a rare entity in pediatrics, in which its clinical findings determine the diagnosis. Taking into account that sometimes it presents ocular alterations, nothing makes us suspect the presence of a specific oral disease(AU)

Abnormal oculocardiac reflex in two patients with Marcus Gunn syndrome.

Marcus Gunn phenomenon is seen in 4 to 6% of congenital ptosis patients. We report two cases of abnormal oculocardiac reflex during ptosis correction surgery. Marcus Gunn syndrome is an autosomal dominant condition with incomplete penetrance. It is believed to be a neural misdirection syndrome in which fibres of the motor division of the trigeminal nerve are congenitally misdirected into the superior pterygoid and the levator muscles. Anesthetic considerations include taking a detailed history about any previous anaesthetic exposure and any reaction to it as this syndrome has a high probability of being associated with malignant hyperthermia. It is also postulated that an atypical oculocardiac reflex might be initiated in these patients as seen in our patients, so precautions must be taken for its prevention and early detection.